Patent Document 1, for example, has proposed a mounting structure for a power module used in the field of power electronics, mainly a motor controller such as an inverter or a servo amplifier operated with high-voltage electric power, the power module including a power semiconductor device that is an exothermic component.
FIG. 2 is a sectional side view showing the existing mounting structure for a power module, FIG. 3 is a sectional side view showing the mounting structure for a power module in FIG. 2 in a state in which screw removal holes for removing the power module are provided to the mounting structure, and FIG. 4 is a sectional side view showing the mounting structure for a power module in FIG. 2 before being assembled.
FIGS. 2, 3, and 4 show printed circuit board fixing screws 1, power module fixing screws 2b, a power module 3, printed circuit boards 4a and 4b, a heat sink 5b, a power module mounting surface 5c, soldered portions 6, screw removal holes 7b, a tool 8b, and heat radiation fins 9b. 
As shown in FIG. 2, after the power module 3 has been fixed to the heat sink 5b with the power module fixing screws 2b, the printed circuit board 4a is connected to the power module 3 by solder at the soldered portions 6. With this mounting structure, in order to separate the power module 3 and the heat sink 5b from each other after the printed circuit board 4a has been connected to the power module 3 by soldering, the solder connecting the power module 3 and the printed circuit board 4a is melted and removed; or, as shown in FIG. 3, the screw removal holes 7b are formed in the printed circuit board 4b, the tool 8b is inserted into the screw removal holes 7b, and the power module fixing screws 2b are removed with the tool 8b. 
Patent Document 1: Japanese Unexamined Patent Application Publication No. 11-274711 (Description pp. 2-3, FIG. 1)